The perforating branches of the internal thoracic artery pierce through the internal intercostal muscles of the superior six intercostal spaces.
These small arteries run with the anterior cutaneous branches of the intercostal nerves.
The perforating arteries constitute part of the blood supply to the pectoralis major and the overlying tissue and skin.
Chung, Kyung Wong, Ph.D. Board Review Series: Gross Anatomy, 3rd ed.
Lockhart, R.D., et al. "Anatomy of the Human Body."